nx_log.nx

nx_log.nx -- structured logging framework. Enterprise-grade replacement for ad-hoc `sys_write(2, "tag"...)`. Design draws from: Google glog / Abseil LOG(INFO) Rust tracing crate (levels, spans, structured fields) Microsoft ETW (schema-typed events, high-throughput capture) syslog RFC 5424 (level taxonomy, tag conventions) OpenTelemetry logs data model (severity + body + attributes) What enterprise-grade means here: * Levels -- TRACE/DEBUG/INFO/WARN/ERROR/FATAL. Compile-time AND runtime gated; call sites below min_level compile to a no-op branch, runtime filters emit to fd or drop. * Tags -- every event carries a module-identifier tag for grep / filter / routing. Mandatory, not optional. * Structured output -- each line is '<seq> <level> <tag> <msg>\n' stable format, greppable, machine-parseable. No ANSI escapes, no timestamps that change builds, no env-specific formatting: F6-reproducible. * Deterministic by default -- monotonic sequence counter, not wall-clock time. Tests can snapshot logs byte-for-byte. * Context object -- multiple logger instances can coexist (e.g., parser log, codegen log, test log). Default global context routes to stderr. * Fatal path -- nx_log_fatal exits with NX_ASSERT_EXIT=200, same code as nx_assert so harnesses handle uniformly. Not yet (staged for follow-ups): * Binary encoding option (ETW-style schema-typed events) * Ring buffer capture + post-mortem dump * Span / scope tracking (entry/exit markers with id) * Field name = value pairs (structured attributes) * Remote sink via socket / shared ring These ship in nx_log_span.nx + nx_log_sink.nx when needed.